In the process of industrial production often can produce a certain pressure and heat of exhaust gas, if direct emissions is not only a waste of energy, and environmental pollution. The tail gas turbine is to take advantage of the tail gas for power generation or drive, to achieve the purpose of energy conservation and environmental protection. Common with the nitric acid tail penetration, PTA, TRT, flue gas through equality.
1) nitric acid tail through
Double pressure nitric acid production has the equipment compact structure, advanced technology, high efficiency, energy saving effect is remarkable and the characteristics of safe and reliable, are now become the first process of nitric acid plant around the world. By axial flow compressor, nitrogen oxide compressor, exhaust gas turbine and steam turbine expander composed of four machine, unit with "four unity" is the core equipment of double pressure nitric acid unit. "Four unity" in the role of double pressure nitric acid production unit is respectively: axial flow compressor will be purified compressed air to 0.45 MPa (A), mixed with ammonia fully into oxidation furnace and combustion reaction generated nitrogen oxide; The nitrogen oxide gas after heat exchange into nitric oxide compressors, compressed to 1.1 MPa (A) after the absorption tower water absorption, and generate A eligible concentration of dilute nitric acid. Escape from the absorption tower of nitric acid tail gas after preheating and overheating and a series of heat transfer process in exhaust energy recovery turbine expander, tail gas from the exhaust vent line after work atmosphere; Steam turbine used in the oxidation of ammonia oxidation with air in furnace of superheated steam to work, to complement the unit between compression work and tail gas expander recycling work in the loss. Of axial flow compressor and nitrogen oxide compressor for power consumption equipment, exhaust gas turbine and steam turbine expander for prime mover, for common driving axial flow compressor and nitrogen oxide compressors.
Exhaust gas turbine expander is the key equipment in the joining together of four unit, process system is accomplished by the throttle pressure. The role of tail gas expander is a collection of nitric acid production process exhaust pressure energy and heat energy, make it into mechanical energy, the second is to convert the mechanical energy to drive the axial flow compressor and nitrogen oxide compressors.
2) PTA tail through
Purified terephthalic acid (PTA) (purified terephthalic acid PTA for short) is the main raw material of polyester production. PTA exhaust turbine with nitric acid as the role of the tail, will be the reaction of exhaust gas pressure and heat recovery, provided with the steam turbine compressor power consumption, unit operation in the process of energy balance, tail through at the same time also to play the role of a pressure adjusting device. Absorb DaChu to exhaust gas after heat exchange in the end through expanding power, by the burning of emissions to the atmosphere. Exhaust gas composition is roughly the same and nitric acid plant tail gas composition, mainly containing nitrogen, and a small amount of carbon dioxide, oxygen and moisture, and some corrosive gases.
3) TRT
Blast Furnace Gas Pressure Recovery Turbine Unit, called the English Blast Furnace Gas Top Pressure Recovery Turbine Unit (TRT). Usually in the blast furnace ironmaking process, produces the high temperature and high pressure blast furnace gas after decompression valve group to send gas users, a large amount of energy is wasted on the pressure reducing valve group, at the same time cause noise pollution. TRT device is to replace the relief valve set to adjust and stabilize the furnace top pressure, the use of blast furnace top gas pressure energy and heat energy, make its expanding power, through the turbine driven generator or other driven equipment for energy recovery. TRT device commonly recycled more than a third of the energy consumption of blast furnace blower, the device in the process of operation does not affect the normal use of the gas users, do not produce pollution, low cost, both have the effect of energy conservation and environmental protection, and bring considerable economic benefit and social benefit for the enterprise.
TRT technology originated in Europe, grown in Japan, including kawasaki heavy industries in technology, leads the world in both quantity and quality. TRT technology research and application in our country began in the late 1970 s, after the application in the mid - 80 - s, along with the test, research continues, many patents of advanced and mature techniques have been mastered by our country. Is a steel producer in China, the energy consumption of iron and steel enterprises, now has more than large and medium-sized not installed blast furnace TRT device, in an increasingly tense energy situation in our country environment, TRT device not only has a broad market, and is good for environmental protection and energy saving.